1. Field of the Invention
The present invention relates to a method for extracting chromium (III) from aqueous solutions containing chromium (III) using a mixture of mono-2-ethylhexyl phosphoric acid and di-2-ethylhexyl phosphoric acid as the extractant.
2. Description of the Prior Art
The extraction of chromium (III) from waste metallurgy process liquor containing chromium (III) such as aqueous sulfuric acid streams is necessary to enable the acid stream to be reclaimed or safely disposed of without pollution.
Reduction of chromium (III) in effluent acid streams requires precipitation by adjusting the pH of the stream to 7.0. Chromium (III) is removed by filtration resulting in a solids waste disposal liability. Also, the post-filtered acid stream has been neutralized having no recycle value. The process requires expensive neutralization chemicals and results in no beneficial/recyclable effluent.